1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/smp_lock.h> 16 #include <linux/init.h> 17 #include <linux/list.h> 18 #include <linux/fs.h> 19 #include <linux/err.h> 20 #include <linux/mount.h> 21 #include <linux/jffs2.h> 22 #include <linux/pagemap.h> 23 #include <linux/mtd/super.h> 24 #include <linux/ctype.h> 25 #include <linux/namei.h> 26 #include <linux/exportfs.h> 27 #include "compr.h" 28 #include "nodelist.h" 29 30 static void jffs2_put_super(struct super_block *); 31 32 static struct kmem_cache *jffs2_inode_cachep; 33 34 static struct inode *jffs2_alloc_inode(struct super_block *sb) 35 { 36 struct jffs2_inode_info *f; 37 38 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 39 if (!f) 40 return NULL; 41 return &f->vfs_inode; 42 } 43 44 static void jffs2_destroy_inode(struct inode *inode) 45 { 46 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 47 } 48 49 static void jffs2_i_init_once(void *foo) 50 { 51 struct jffs2_inode_info *f = foo; 52 53 mutex_init(&f->sem); 54 inode_init_once(&f->vfs_inode); 55 } 56 57 static void jffs2_write_super(struct super_block *sb) 58 { 59 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 60 61 lock_super(sb); 62 sb->s_dirt = 0; 63 64 if (!(sb->s_flags & MS_RDONLY)) { 65 D1(printk(KERN_DEBUG "jffs2_write_super()\n")); 66 jffs2_garbage_collect_trigger(c); 67 jffs2_erase_pending_blocks(c, 0); 68 jffs2_flush_wbuf_gc(c, 0); 69 } 70 71 unlock_super(sb); 72 } 73 74 static int jffs2_sync_fs(struct super_block *sb, int wait) 75 { 76 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 77 78 jffs2_write_super(sb); 79 80 mutex_lock(&c->alloc_sem); 81 jffs2_flush_wbuf_pad(c); 82 mutex_unlock(&c->alloc_sem); 83 return 0; 84 } 85 86 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 87 uint32_t generation) 88 { 89 /* We don't care about i_generation. We'll destroy the flash 90 before we start re-using inode numbers anyway. And even 91 if that wasn't true, we'd have other problems...*/ 92 return jffs2_iget(sb, ino); 93 } 94 95 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 96 int fh_len, int fh_type) 97 { 98 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 99 jffs2_nfs_get_inode); 100 } 101 102 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 103 int fh_len, int fh_type) 104 { 105 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 106 jffs2_nfs_get_inode); 107 } 108 109 static struct dentry *jffs2_get_parent(struct dentry *child) 110 { 111 struct jffs2_inode_info *f; 112 uint32_t pino; 113 114 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 115 116 f = JFFS2_INODE_INFO(child->d_inode); 117 118 pino = f->inocache->pino_nlink; 119 120 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 121 f->inocache->ino, pino); 122 123 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 124 } 125 126 static const struct export_operations jffs2_export_ops = { 127 .get_parent = jffs2_get_parent, 128 .fh_to_dentry = jffs2_fh_to_dentry, 129 .fh_to_parent = jffs2_fh_to_parent, 130 }; 131 132 static const struct super_operations jffs2_super_operations = 133 { 134 .alloc_inode = jffs2_alloc_inode, 135 .destroy_inode =jffs2_destroy_inode, 136 .put_super = jffs2_put_super, 137 .write_super = jffs2_write_super, 138 .statfs = jffs2_statfs, 139 .remount_fs = jffs2_remount_fs, 140 .clear_inode = jffs2_clear_inode, 141 .dirty_inode = jffs2_dirty_inode, 142 .sync_fs = jffs2_sync_fs, 143 }; 144 145 /* 146 * fill in the superblock 147 */ 148 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 149 { 150 struct jffs2_sb_info *c; 151 152 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" 153 " New superblock for device %d (\"%s\")\n", 154 sb->s_mtd->index, sb->s_mtd->name)); 155 156 c = kzalloc(sizeof(*c), GFP_KERNEL); 157 if (!c) 158 return -ENOMEM; 159 160 c->mtd = sb->s_mtd; 161 c->os_priv = sb; 162 sb->s_fs_info = c; 163 164 /* Initialize JFFS2 superblock locks, the further initialization will 165 * be done later */ 166 mutex_init(&c->alloc_sem); 167 mutex_init(&c->erase_free_sem); 168 init_waitqueue_head(&c->erase_wait); 169 init_waitqueue_head(&c->inocache_wq); 170 spin_lock_init(&c->erase_completion_lock); 171 spin_lock_init(&c->inocache_lock); 172 173 sb->s_op = &jffs2_super_operations; 174 sb->s_export_op = &jffs2_export_ops; 175 sb->s_flags = sb->s_flags | MS_NOATIME; 176 sb->s_xattr = jffs2_xattr_handlers; 177 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 178 sb->s_flags |= MS_POSIXACL; 179 #endif 180 return jffs2_do_fill_super(sb, data, silent); 181 } 182 183 static int jffs2_get_sb(struct file_system_type *fs_type, 184 int flags, const char *dev_name, 185 void *data, struct vfsmount *mnt) 186 { 187 return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super, 188 mnt); 189 } 190 191 static void jffs2_put_super (struct super_block *sb) 192 { 193 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 194 195 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 196 197 lock_kernel(); 198 199 if (sb->s_dirt) 200 jffs2_write_super(sb); 201 202 mutex_lock(&c->alloc_sem); 203 jffs2_flush_wbuf_pad(c); 204 mutex_unlock(&c->alloc_sem); 205 206 jffs2_sum_exit(c); 207 208 jffs2_free_ino_caches(c); 209 jffs2_free_raw_node_refs(c); 210 if (jffs2_blocks_use_vmalloc(c)) 211 vfree(c->blocks); 212 else 213 kfree(c->blocks); 214 jffs2_flash_cleanup(c); 215 kfree(c->inocache_list); 216 jffs2_clear_xattr_subsystem(c); 217 if (c->mtd->sync) 218 c->mtd->sync(c->mtd); 219 220 unlock_kernel(); 221 222 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 223 } 224 225 static void jffs2_kill_sb(struct super_block *sb) 226 { 227 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 228 if (!(sb->s_flags & MS_RDONLY)) 229 jffs2_stop_garbage_collect_thread(c); 230 kill_mtd_super(sb); 231 kfree(c); 232 } 233 234 static struct file_system_type jffs2_fs_type = { 235 .owner = THIS_MODULE, 236 .name = "jffs2", 237 .get_sb = jffs2_get_sb, 238 .kill_sb = jffs2_kill_sb, 239 }; 240 241 static int __init init_jffs2_fs(void) 242 { 243 int ret; 244 245 /* Paranoia checks for on-medium structures. If we ask GCC 246 to pack them with __attribute__((packed)) then it _also_ 247 assumes that they're not aligned -- so it emits crappy 248 code on some architectures. Ideally we want an attribute 249 which means just 'no padding', without the alignment 250 thing. But GCC doesn't have that -- we have to just 251 hope the structs are the right sizes, instead. */ 252 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 253 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 254 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 255 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 256 257 printk(KERN_INFO "JFFS2 version 2.2." 258 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 259 " (NAND)" 260 #endif 261 #ifdef CONFIG_JFFS2_SUMMARY 262 " (SUMMARY) " 263 #endif 264 " © 2001-2006 Red Hat, Inc.\n"); 265 266 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 267 sizeof(struct jffs2_inode_info), 268 0, (SLAB_RECLAIM_ACCOUNT| 269 SLAB_MEM_SPREAD), 270 jffs2_i_init_once); 271 if (!jffs2_inode_cachep) { 272 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 273 return -ENOMEM; 274 } 275 ret = jffs2_compressors_init(); 276 if (ret) { 277 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 278 goto out; 279 } 280 ret = jffs2_create_slab_caches(); 281 if (ret) { 282 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 283 goto out_compressors; 284 } 285 ret = register_filesystem(&jffs2_fs_type); 286 if (ret) { 287 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 288 goto out_slab; 289 } 290 return 0; 291 292 out_slab: 293 jffs2_destroy_slab_caches(); 294 out_compressors: 295 jffs2_compressors_exit(); 296 out: 297 kmem_cache_destroy(jffs2_inode_cachep); 298 return ret; 299 } 300 301 static void __exit exit_jffs2_fs(void) 302 { 303 unregister_filesystem(&jffs2_fs_type); 304 jffs2_destroy_slab_caches(); 305 jffs2_compressors_exit(); 306 kmem_cache_destroy(jffs2_inode_cachep); 307 } 308 309 module_init(init_jffs2_fs); 310 module_exit(exit_jffs2_fs); 311 312 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 313 MODULE_AUTHOR("Red Hat, Inc."); 314 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 315 // the sake of this tag. It's Free Software. 316